SixLabors ImageSharp 2.1.0/4.1.1 TIFF CCITT Group 4 Encoder TiffCcittCompressor.WriteCode out-of-bounds write

Summaryinfo

A vulnerability was found in SixLabors ImageSharp 2.1.0/4.1.1. It has been classified as critical. The impacted element is the function TiffCcittCompressor.WriteCode of the component TIFF CCITT Group 4 Encoder. The manipulation leads to out-of-bounds write. This vulnerability is uniquely identified as CVE-2026-106115. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in SixLabors ImageSharp 2.1.0/4.1.1. It has been rated as critical. This issue affects the function TiffCcittCompressor.WriteCode of the component TIFF CCITT Group 4 Encoder. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

ImageSharp is a 2D graphics library. From 2.1.0 until 4.1.2, the TIFF CCITT Group 4 encoder allocates Width times rowsPerStrip bytes even though T6BitCompressor.CompressStrip can emit encoded row data and two 12-bit end-of-facsimile-block codes beyond that capacity. TiffCcittCompressor.WriteCode performs unchecked writes, and a decode-and-re-encode flow can inherit TiffCompression.CcittGroup4Fax and one-bit metadata from attacker-supplied input. The resulting out-of-bounds writes can corrupt memory and terminate the process. This issue is fixed in version 4.1.2.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-106115 since 10/06/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available.

Upgrading to version 4.1.2 eliminates this vulnerability.

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Productinfo

Vendor

• SixLabors

Name

• ImageSharp

Version

• 2.1.0
• 4.1.1

Website

• Product: https://github.com/SixLabors/ImageSharp/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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